212 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 2 



season the box elder aphis, Chaitopliorus negundinis, was very common 

 on the box elder trees in various parts of the state. The Buffalo tree- 

 hopper, Ceresa huhalns, continues to be abundant on young apple trees 

 in orchards, causing serious losses to young apple trees every year. 

 One orchard of fifty acres of j'oung apple trees at West Branch, 

 Iowa, was severely injured by the work of this insect. Clean culture 

 in the orchards is advised against this pest. 



President Forbes: These three papers are now open for discus- 

 sion. 



Mr, Washburn: The paper by Mr. Webster interests me because 

 he deals with insects that we have in ^Minnesota. We have not been 

 able to find the fall eggs of MacrosipJium granaria so far. Last year 

 Mr. Vickery found females producing young under snow, about the 

 tenth of December, and this year we have found the same thing. 

 And in the inseetary, where the themometer had been down to five 

 below zero, on the same date, December 10, we found the same condi- 

 tion, but no eggs. We have not been able so far to find any winter 

 eggs. We find eggs of Toxoptera and the question arises, is T. grami- 

 nuni really a visitor from the south? We find it awaj^ up to the 

 northern border, and the fact that the eggs survive the winter and 

 hatch in the spring would seem to indicate that it is with us all the 

 time. 



Mr. R. L. Webster : I found only the winged forms of Macro- 

 siphuni granaria early in the year in Iowa and jMinnesota. In what 

 form did you find it first this spring? 



]\Ir. Washburn : I believe they were winged forms. 



Mr. Cooley : Mr. President, I have an idea that there will be found 

 an alternation of generations in MacrosipJium. 



;Mr. Kelly: I think that j\Ir. Cooley has undoubtedly found the 

 eggs of Macrosiphum at Bozeman, jMontana. 



Mr. Sanderson : We got the eggs in May or June in Texas, in the 

 laboratory, from two or three different lots, but we never could find 

 any trace of them in the field. 



]\Ir. Slingerland : I was interested in the application and mixing 

 of kerosene emulsion. I have a few stunts that I put the boys through 

 in the practical mixing of insecticides, and you would be surprised at 

 the arithmetic they sometimes use in making up kerosene emulsion. 

 I believe it is very important for them to realize the necessity for ac- 

 curacy in mixing kerosene emulsion. 



Mr, Sherman: If the college student has all that trouble, how 



